"THERE'S STRONG," as the ads say, "and then there's Army strong." So it's not surprising that Army sergeant Christopher Lavezza is one of the best horse-pickers in the world. While stationed in Afghanistan last spring, Lavezza, 32, an information technology specialist at the Joint Intelligence Operations Center at Camp Eggers in Kabul, found a way to deal with the rigors of his deployment. The native of Hanover, Pa., spent his free time on the Internet playing the ponies back in the U.S. Last spring, with the help of two long shots at Churchill Downs, he placed fourth in a qualifying competition for the National Handicapping Championship, earning a berth in this weekend's finals in Las Vegas. "I worked mostly on night shifts," says Lavezza, who will travel to Vegas from Stuttgart, Germany, where he's stationed with the 52nd Signal Battalion. "It gave me extra downtime." He'll be a long shot himself in Vegas, competing for the $500,000 first prize against 277 other plungers.